GitLab has an advanced log system where everything is logged so that you can analyze your instance using various system log files. In addition to system log files, GitLab Enterprise Edition comes with Audit Events. Find more about them in Audit Events documentation

System log files are typically plain text in a standard log file format. This guide talks about how to read and use these system log files.

This file lives in /var/log/gitlab/gitlab-rails/production.log for Omnibus GitLab packages or in /home/git/gitlab/log/production.log for installations from source. (When Gitlab is running in an environment other than production, the corresponding logfile is shown here.)

It contains information about all performed requests. You can see the URL and type of request, IP address and what exactly parts of code were involved to service this particular request. Also you can see all SQL request that have been performed and how much time it took. This task is more useful for GitLab contributors and developers. Use part of this log file when you are going to report bug. For example:

In this example we can see that server processed an HTTP request with URL /gitlabhq/yaml_db/tree/master from IP 168.111.56.1 at 2015-02-12 19:34:53 +0200. Also we can see that request was processed by Projects::TreeController.

This file lives in /var/log/gitlab/gitlab-rails/githost.log for Omnibus GitLab packages or in /home/git/gitlab/log/githost.log for installations from source.

GitLab has to interact with Git repositories but in some rare cases something can go wrong and in this case you will know what exactly happened. This log file contains all failed requests from GitLab to Git repositories. In the majority of cases this file will be useful for developers only. For example:

This file lives in /var/log/gitlab/unicorn/unicorn_stderr.log for Omnibus GitLab packages or in /home/git/gitlab/log/unicorn_stderr.log for installations from source.

Unicorn is a high-performance forking Web server which is used for serving the GitLab application. You can look at this log if, for example, your application does not respond. This log contains all information about the state of unicorn processes at any given time.